Osmoregulation in Animals

The regulation of solute concentration and water balance within an organism's internal environment.

The process of removing metabolic waste products from the body, such as nitrogenous waste.

Animals that maintain a constant internal osmolarity, regardless of the external environment. They expend energy to control water uptake or loss.

Animals that have an internal osmolarity that is the same as their external environment. They do not actively regulate their osmolarity.

The total concentration of all solutes in a solution, determining the movement of water across a selectively permeable membrane.

The movement of water across a selectively permeable membrane from a region of higher water concentration to a region of lower water concentration.

Animals that can tolerate only a narrow range of salinity.

Animals that can tolerate a wide range of salinity.

Aquatic animals that live in freshwater environments constantly absorb water by osmosis and lose salts by diffusion. They compensate by excreting large amounts of dilute urine.

Aquatic invertebrates that survive in temporary ponds by losing almost all their body water and entering a dormant state.

Land animals obtain water through drinking, eating moist foods, and metabolic processes (water produced during respiration).

The process of regulating the composition of body fluids by specialized epithelial cells called transport epithelia.

Seabirds eliminate excess salt through specialized salt glands that remove sodium chloride from the blood.

The type and amount of nitrogenous waste produced by an animal are influenced by its evolutionary history and environment.

Osmoregulators must expend energy to maintain osmotic gradients. These gradients regulate the movement of water and solutes across cell membranes.

Ammonia is the most toxic form of nitrogenous waste. It requires a large amount of water for excretion and is common in aquatic animals.

Urea is a less toxic form of nitrogenous waste compared to ammonia. It's produced in the liver of mammals and most adult amphibians and requires less water for excretion.

Uric acid is the least toxic form of nitrogenous waste. It's mainly excreted by reptiles, birds, insects, and land snails. It's insoluble in water and can be excreted as a paste with very little water loss.

The conversion of ammonia into urea is an energetically expensive process, but it allows animals to conserve water.

Excretory systems play a crucial role in regulating the balance of solutes and water within an organism, ensuring its internal environment is stable.

Most excretory systems create urine by filtering waste products from bodily fluids. This filtrate is then refined and concentrated to remove excess solutes and produce urine.

Excretory systems in various organisms are fundamentally similar, often built around a system of tubules for filtering and refining waste.

The composition of nitrogenous waste in different animals is related to their habitat, energy needs, and evolutionary adaptations.

A network of dead-end tubules connected to external openings, with cellular units called flame bulbs at the smallest branches, responsible for excreting dilute fluids and osmoregulation.

Open-ended tubules in each segment of an earthworm that collect coelomic fluid and produce dilute urine for excretion and osmoregulation.

Tubules in insects and other terrestrial arthropods remove nitrogenous wastes from hemolymph and play a role in osmoregulation. They open into the digestive tract.

The functional unit of the vertebrate kidney, consisting of a long tubule and a ball of capillaries called the glomerulus.

The process by which blood pressure forces fluid from the blood in the glomerulus into the lumen of Bowman's capsule.

The process of reclaiming valuable solutes from the filtrate back into the blood.

The process of adding toxins and unwanted solutes from the body fluids to the filtrate.

The removal of the filtrate from the excretory system.

The initial fluid filtered from the blood in the glomerulus, containing water, salts, glucose, amino acids, and other small molecules.

A specialized capillary network that surrounds the loop of Henle, playing a crucial role in water reabsorption.

A countercurrent system between the loop of Henle and the vasa recta, allowing for highly concentrated urine production.

The first part of the nephron where most of the reabsorption of water, ions, and nutrients occurs. It also secretes waste products.

The descending limb of the loop of Henle allows water to pass out, making the filtrate more concentrated.

The ascending limb of the loop of Henle allows salt to pass out, making the filtrate more dilute.

The final part of the nephron where the fine-tuning of ion and water balance takes place. It helps regulate blood pressure.

The collecting duct carries the final filtrate through the medulla, allowing for further concentration of urine.